69,580 research outputs found
Cellular Underwater Wireless Optical CDMA Network: Potentials and Challenges
Underwater wireless optical communications is an emerging solution to the
expanding demand for broadband links in oceans and seas. In this paper, a
cellular underwater wireless optical code division multiple-access (UW-OCDMA)
network is proposed to provide broadband links for commercial and military
applications. The optical orthogonal codes (OOC) are employed as signature
codes of underwater mobile users. Fundamental key aspects of the network such
as its backhaul architecture, its potential applications and its design
challenges are presented. In particular, the proposed network is used as
infrastructure of centralized, decentralized and relay-assisted underwater
sensor networks for high-speed real-time monitoring. Furthermore, a promising
underwater localization and positioning scheme based on this cellular network
is presented. Finally, probable design challenges such as cell edge coverage,
blockage avoidance, power control and increasing the network capacity are
addressed.Comment: 11 pages, 10 figure
Geotechnical Characterization of TriNet Sites: A Status Report
The TriNet project, launched in 1997, created an improved,
real-time seismic monitoring network in Southern California.
Planning of the network began in 1995 (e.g., Heaton et
al., 1996), building on the success of the earlier TERRAscope network, which included 24 digital broadband and strongmotion instruments throughout Southern California (e.g., Kanamori et al., 1993). At the end of the five-year TriNet project the network comprised 150 real-time digital broadband stations and another 400 strong-motion sensors, 50 of which were also real-time. This network is now recording digital broadband data for Southern California earthquakes at an unprecedented rate, data that are already proving valuable for investigations of earthquake sources and regional wave propagation, as well as earthquake response
Data-Driven Emulation of Mobile Access Networks
Network monitoring is fundamental to understand network evolution and behavior. However, monitoring studies have the main limitation of running new experiments when the phenomenon under analysis is over e.g., congestion. To overcome this limitation, network emulation is of vital importance for network testing and research experiments either in wired and mobile networks. When it comes to mobile networks, the variety of technical characteristics, coupled with the opaque network configurations, make realistic network emulation a challenging task. In this paper, we address this issue leveraging a large scale dataset composed of 500M network latency measurements in Mobile BroadBand networks. By using this dataset, we create 51 different network latency profiles based on the Mobile BroadBand operator, the radio access technology and signal strength. These profiles are then processed to make them compatible with the tc-netem emulation tool. Finally, we show that, despite the limitation of current tc-netem emulation tool, Generative Adversarial Networks are a promising solution used to create realistic temporal emulation. We believe that this work could be the first step toward a comprehensive data-driven network emulation. For this, we make our profiles and codes available to foster further studies in these directions
Quality of service monitoring: Performance metrics across proprietary content domains
We propose a quality of service (QoS) monitoring program for broadband access
to measure the impact of proprietary network spaces. Our paper surveys other
QoS policy initiatives, including those in the airline, and wireless and
wireline telephone industries, to situate broadband in the context of other
markets undergoing regulatory devolution. We illustrate how network
architecture can create impediments to open communications, and how QoS
monitoring can detect such effects. We present data from a field test of
QoS-monitoring software now in development. We suggest QoS metrics to gauge
whether information "walled gardens" represent a real threat for dividing the
Internet into proprietary spaces.
To demonstrate our proposal, we are placing our software on the computers of
a sample of broadband subscribers. The software periodically conducts a battery
of tests that assess the quality of connections from the subscriber's computer
to various content sites. Any systematic differences in connection quality
between affiliated and non-affiliated content sites would warrant research into
the behavioral implications of those differences.
QoS monitoring is timely because the potential for the Internet to break into
a loose network of proprietary content domains appears stronger than ever.
Recent court rulings and policy statements suggest a growing trend towards
relaxed scrutiny of mergers and the easing or elimination of content ownership
rules. This policy environment could lead to a market with a small number of
large, vertically integrated network operators, each pushing its proprietary
content on subscribers.Comment: 29th TPRC Conference, 200
Exploring Broadband Enabled Smart eEnvironment: Wireless Sensor (Mesh) Network
This paper explored the emergent importance of the use sensors as complementary or as alternative to environmental sensing and monitoring, industrial monitoring, and surface explorations. Advances in wireless broadband technology have enabled the use Wireless Sensor (Mesh) Network (WSN), a type mobile ad hoc network (MANET), in all facet of human endeavor. As a next-generation wireless communication, which centered on energy savings, communication reliability, and security, WSN has increased our processing, sensing, and communications capabilities. Hence, this paper is an exploration of recent reliance on sensors as result of broadband enabled smart environment for activities, such as environmental and habitat monitory, military surveillance, target tracking, search and rescue, and logistical tracking and supply-chain management
MedNet status report
MedNet is a network of very broadband seismic stations installed in countries bordering the Mediterranean area. The project started in 1987, with a final goal of 12-15 stations and a spacing of about 1000 km between stations. It was motivated both by research interest and by seismic hazard monitoring.
The network presently comprises 23 operating stations, all of them equipped with state of the art seismographic stations.
Presently, fully automatic network functions include:
- daily monitoring of state of health;
- data recover after link failures;
- triggered retrieval of event waveforms;
- update of web pages (http://mednet.ingv.it) for events and station information.PublishedS. Fernando (SPAIN)1.1. TTC - Monitoraggio sismico del territorio nazionaleope
Seismological monitoring of Campi Flegrei caldera
Campi Flegrei is an active volcanic area posing a serious threat over Naples. Half of
the city lies inside the caldera rim. The volcano has shown in the last 30 years different
episodes of unrest, the most recent is still ongoing. For this reason the monitoring of
this volcano is a fundamental task. The current seismic network consists of 8 short
period and 5 broadband stations. The seismic monitoring is complemented by 2 infrasonic
sensors and 3 dilatometers. The recent seismicity has been characterized by
swarms of volcano-tectonic and long-period events. The network geometry allows an
accurate location of VT events with a detection threshold of magnitudes less than 1.0
Some VT events have been recorder also by the infrasonic sensors showing interesting
similarities. LP events have been recorded by both short period and broadband
stations. The polarization analysis performed over the broadband recordings is an important
tool for the real time detection of such events, related to the dynamics of the
hydrothermal system. The ongoing developments consists in a progressive increasing
of the number of broadband digital stations and infrasonic sensors, in improving the
accuracy of hypocenter locations by using a 3D velocity model and in the implementation
of new automatic techniques aimed at the detection, classification and analysis
of seismic events.PublishedVienna, Austria1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope
Transmission Delay of Multi-hop Heterogeneous Networks for Medical Applications
Nowadays, with increase in ageing population, Health care market keeps
growing. There is a need for monitoring of Health issues. Body Area Network
consists of wireless sensors attached on or inside human body for monitoring
vital Health related problems e.g, Electro Cardiogram (ECG),
ElectroEncephalogram (EEG), ElectronyStagmography(ENG) etc. Data is recorded by
sensors and is sent towards Health care center. Due to life threatening
situations, timely sending of data is essential. For data to reach Health care
center, there must be a proper way of sending data through reliable connection
and with minimum delay. In this paper transmission delay of different paths,
through which data is sent from sensor to Health care center over heterogeneous
multi-hop wireless channel is analyzed. Data of medical related diseases is
sent through three different paths. In all three paths, data from sensors first
reaches ZigBee, which is the common link in all three paths. After ZigBee there
are three available networks, through which data is sent. Wireless Local Area
Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX),
Universal Mobile Telecommunication System (UMTS) are connected with ZigBee.
Each network (WLAN, WiMAX, UMTS) is setup according to environmental
conditions, suitability of device and availability of structure for that
device. Data from these networks is sent to IP-Cloud, which is further
connected to Health care center. Main aim of this paper is to calculate delay
of each link in each path over multihop wireless channel.Comment: BioSPAN with 7th IEEE International Conference on Broadband and
Wireless Computing, Communication and Applications (BWCCA 2012), Victoria,
Canada, 201
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